\begin{tikzpicture}
	\pgfmathsetmacro{\r}{2.5}
	\pgfmathsetmacro{\a}{55}
	\pgfmathsetmacro{\b}{35}

	\begin{scope}
		\tkzDefPoints{0/0/B, \r/0/A}
		\tkzDefPoint(\a:\r){C}
		\tkzDrawSegments(B,A  B,C)
		\tkzMarkAngle[size=0.5](A,B,C)
		\tkzLabelAngle[pos=0.8](A,B,C){$1$}
	\end{scope}

	\begin{scope}[xshift=4cm]
		\tkzDefPoints{0/0/B, \r/0/A}
		\tkzDefPoint(\b:\r){C}
		\tkzDrawSegments(B,A  B,C)
		\tkzMarkAngle[size=0.5](A,B,C)
		\tkzLabelAngle[pos=0.8](A,B,C){$2$}
	\end{scope}

	\begin{scope}[xshift=8cm]
		\tkzDefPoints{0/0/B, \r/0/A}
		\tkzDefPoint(\b:\r){C}
		\tkzDrawSegments(B,A  B,C)
		\tkzMarkAngle[size=0.5](A,B,C)
		\tkzLabelAngle[pos=0.8](A,B,C){$3$}
	\end{scope}
\end{tikzpicture}

